When four men gun down Emmett Spears in cold blood in a saloon in Harper, Colorado, his best friend, Wade Garrison, makes a promise of revenge. Sarah Talbert loves Wade and pleads with him not to go, but he had made a promise to Emmett, and he intends to keep that promise.

Wade Garrison is a man who never knew hatred, but now it consumes him. Armed with a pistol and Sharps .50-caliber rifle, he walks away from Sarah and goes after the four men. He follows their trail of violence across Colorado, New Mexico, Arizona, and Mexico.